lttng-ust(3): document `perf:thread:raw:rN:NAME` context

[lttng-ust.git] / doc / man / lttng-ust.3.txt

diff --git a/doc/man/lttng-ust.3.txt b/doc/man/lttng-ust.3.txt
index 8ecda775b3477f363a8c234109e4d9a95802f67d..0593406a857a1ccf68cce4875239faa2c7fb3c25 100644 (file)
--- a/doc/man/lttng-ust.3.txt
+++ b/doc/man/lttng-ust.3.txt
@@ -738,6 +738,12 @@ without a following man:exec(3) family system call. The library
 application with the `LD_PRELOAD` environment variable (see
 man:ld.so(8)).
 
+To use `liblttng-ust` with a daemon application which closes file
+descriptors that were not opened by it, preload the `liblttng-ust-fd.so`
+library before you start the application. Typical use cases include
+daemons closing all file descriptors after man:fork(2), and buggy
+applications doing ``double-closes''.
+
 
 Context information
 ~~~~~~~~~~~~~~~~~~~
@@ -763,12 +769,16 @@ information about event filtering.
     reverse-lookup the source location that caused the event
     to be emitted.
 
-+perf:thread:COUNTER+::
+`perf:thread:COUNTER`::
     perf counter named 'COUNTER'. Use `lttng add-context --list` to
     list the available perf counters.
 +
 Only available on IA-32 and x86-64 architectures.
 
+`perf:thread:raw:rN:NAME`::
+    perf counter with raw ID 'N' and custom name 'NAME'. See
+    man:lttng-add-context(1) for more details.
+
 `pthread_id`::
     POSIX thread identifier. Can be used on architectures where
     `pthread_t` maps nicely to an `unsigned long` type.